Abstract
The compound undergoes a metal-to-insulator transition for . It is known that disorder alone is insufficient to explain this transition; e.g., a quantum site percolation model predicts . We have included (Hubbard) electronic interactions into a model of this compound, using a real-space Hartree-Fock approach that achieves self-consistency at every site, and have found that for a Hubbard energy equal to 1.5 times the non-interacting bandwidth one obtains . Further, with increasing Hubbard energy we find an Altshuler-Aronov suppression of the density of states, , that reduces the density of states at the Fermi energy to zero at the critical Hubbard interaction. Using this ratio of correlation to hopping energy one is led to a prediction of the near-neighbor superexchange () which is similar to that for the cuprate superconductors.
- Received 15 November 2005
DOI:https://doi.org/10.1103/PhysRevLett.96.046410
©2006 American Physical Society